Databases are used to store a variety of information. For example, databases may track financial transactions, errors occurring in a computer system, and changes to a document file. These databases are often essential to the operation of a company. Thus, the databases must save information, such that the information is quickly accessible on demand. Further, the databases must be fault-tolerant to prevent unnecessary downtime of the company. Virtual tape libraries (VTLs) are one storage device capable of storing these large databases.
Virtual tape library (VTL) solutions are advantageous over physical, sequential-access tape storage technologies. A VTL presents random-access mass storage to large computing systems, as if they were physical tape devices and media. They are generally attached through existing host operating system interfaces. They may be treated as normal tape volumes, and therefore require no operating system-level changes, because these tape volumes and drives are emulated instances of real media/tape devices. VTLs also reduce operator intervention, as no tape volumes need be manually located and mounted before they may be used.
However, despite all these advantages, VTLs do introduce monitoring requirements beyond those presented by physical tape devices and media. That is because the VTL server is a computing system, and is accompanied by the similar complexities and failure points of a computing system. A separate VTL Library Controller is also required in some implementations.
Complex systems, such as a VTL, require system- and network-level monitoring when companies come to rely on them for crucial business functions. A system operator, or often a team of shift workers, constantly monitors VTL operations directly, either by submitting VTL status commands or by watching separate monitoring tools. This is a highly manual and expensive approach to system monitoring, as a paid employee must be constantly deployed to sustain 24-hour vigilance. Further, this manual method does not scale well, as few individuals may monitor more than a handful of VTL systems without suffering productivity degradation. Many businesses may implement not one VTL, but many, as replication and resiliency are required for such a crucial subsystem. This increases the monitoring requirements in an exponential fashion for large, complex organizations with remote Disaster Recovery (DR) sites.